Environmental Stress, Social Networks, and Older Age Health and Mortality This project will investigate how early life environmental stress affects older age morbidity and mortality, and how social networks mediate the effects of stress. This project will provide a better understanding of how risk factors, protective factors, and early-life experience affect long-run health outcomes. A better understanding of health pathways may allow us to manipulate early risk factors and protective factors and may lead us to increase health investments at younger ages. A better understanding of senescent processes will also inform our predictions of older age mortality and morbidity trends and therefore has implications for our predictions of future pension and health care costs. This project is unique in its ability to examine earlier life events, older age mortality and physician-assessed morbidity, and detailed measures of social networks all within the same dataset. Specifically, this project will study environmental stress by examining the older age morbidity and mortality effects of wartime stress and POW status and determining how company cohesion and community and family support mediate the effects of stress. The project will examine 1) how POW status affected mortality and morbidity at ages 50 and over;2) how wartime stress should be measured and how wartime stress affected disease and death at ages 50 and over;and, 3) how individual, company, family, and community characteristics such as individual health declines, company cohesion, the death of a spouse, and community support for the war mediated the effects of POW status and wartime stress on older age mortality and morbidity. The project will use longitudinal data on 39,616 Union Army veterans and a longitudinal dataset of 2,000 Andersonville survivors that will be created as part of this project. These datasets provide a unique opportunity to study the long-term scarring effects of POW status and wartime stress because the full life history of these men from early youth to death is observed, including detailed medical records at older ages. Because there was considerable variation in POW and wartime experience during the Civil War, the data provide several control groups for examining the effects of extreme stress.